Soft-body simulation, particularly cloth simulation, has become a desirable feature for video games that wish to be graphically competitive. Unlike simulations for film visual effects, video games provide real-time cloth simulations which have to operate under severe resource constraints and look good under all possible user input. In video games, cloth is often attached to characters that can move at superhuman speeds so the robustness requirements on the simulation can be quite restrictive. Real-time cloth simulation in video games, therefore, warrants different techniques from techniques used in work such as film rendering and academia.